Solenoid, damping force adjustment mechanism, and damping force adjustable shock absorber

A damping force adjustment mechanism comprising:

• a coil wound annularly and configured to generate a magnetic force in reaction to power supply;
• a housing member disposed on an inner periphery of the coil, the housing member extending in a direction of a winding axis of the coil, the housing member including a housing portion opened on one end side thereof and being made from a magnetic body;
• a movable element provided in the housing portion movably in the direction of the winding axis of the coil, the movable element being made from a magnetic body;
• a control valve configured to be controlled according to a movement of the movable element;
• a stator provided at a position facing the opening of the housing portion, the stator including a reduced diameter portion and a side surface portion integrally made from a magnetic body, the reduced diameter portion having an outer diameter reducing as it is approaching the opening of the housing portion, the side surface portion extending from an outer periphery of the reduced diameter portion in a direction away from the opening of the housing portion;
• and
• a yoke including a fixation hole having an inner peripheral surface to which a part of the side surface portion of the stator is fixed, the yoke being configured in such a manner that a non-contact portion, where an annular space is defined in an assembled state and the yoke and the side surface portion of the stator are out of contact with each other, is formed between the yoke and the side surface portion of the stator on the housing member side of the fixation hole.

A damping force adjustable shock absorber comprising:

• a cylinder sealingly containing hydraulic fluid therein;
• a piston provided slidably in the cylinder;
• a piston rod coupled with the piston and extending out of the cylinder;
• and
• a damping force adjustment mechanism configured to generate a damping force by controlling a flow of the hydraulic fluid that is generated according to a sliding movement of the piston in the cylinder,
• wherein the damping force adjustment mechanism includes
• a coil wound annularly and configured to generate a magnetic force in reaction to power supply,
• a housing member disposed on an inner periphery of the coil, the housing member extending in a direction of a winding axis of the coil, the housing member including a housing portion opened on one end side thereof and being made from a magnetic body,
• a movable element provided in the housing portion movably in the direction of the winding axis of the coil, the movable element being made from a magnetic body,
• a control valve configured to be controlled according to a movement of the movable element,
• a stator provided at a position facing the opening of the housing portion, the stator including a reduced diameter portion and a side surface portion integrally made from a magnetic body, the reduced diameter portion having an outer diameter reducing as it is approaching the opening of the housing portion, the side surface portion extending from an outer periphery of the reduced diameter portion in a direction away from the opening of the housing portion, and
• a yoke including a fixation hole having an inner peripheral surface to which a part of the side surface portion of the stator is fixed, the yoke being configured in such a manner that a non-contact portion, where an annular space is defined in an assembled state and the yoke and the side surface portion of the stator are out of contact with each other, is formed between the yoke and the side surface portion of the stator on the housing member side of the fixation hole.